Socket



April 15, 1941. M. ALDEN 2,238,152

\ SOCKET Filed Sept. 5, 1940 INVENTOR Mi/fon [Udell @gNEY Patented Apr. 15, 1941 UNITED STATES PATENT OFFICE SOCKET Milton Alden, Brockton, Mass. Application September 5, 1940, Serial No. 355,414

6 Claims.

This invention relates to lamp sockets of the type adapted to receive a lamp base having two projecting pins, affording electrical connection between the socket and the interior of the lamp.

The socket of thisinvention is especially adapted to receive one end of a lamp of the fluorescent type, such lamps being usually provided with at least two pins upon each end of the lamp, each end being inserted into a discrete socket.

This invention embodies certain features shown in my copending application Serial No. 333,086 filed May 3, 1940.

One purpose of this invention is to provide a socket of the type described which shall allow the easy insertion of the lamp prongs or pins therein, without the possibility that such pins may enter the socket in an incorrect fashion, so asto cause physical damage to the lamp, its base, or the socket, or so as to make incorrect electrical connections which might damage the lamp.

Another purpose of my invention is to provide a socket into which a lamp base can be inserted in such fashion that no electrical connections will be made during the bodily movement of translation of the lamp, and such connection will only occur upon a rotational movement of the lamp, subsequent to the initial insertion into the socket. In this fashion is avoided the possibility of undesired premature excitation of the lamp, in. case that the socket terminals are alive" when the lamp is being inserted, fluorescent lamps being easily damaged by premature and uncertain connections which may easily occur under such circumstances.

A further object of my invention is to provide a socket in which the actual connection of the lamp pins to the terminals of the socket occurs suddenly with a snap action, while the lamp is being rotated, thus assuring that both ends of the lamp are connected substantially at the same instant in a positive and relatively sudden fashion, and avoiding troubles of the character above mentioned, in case that the sockets have not been switched off from the power supply before insertion of the lamp into the sockets.

Yet another object of the invention is to provide a socket of the character described in which the lamp may readily be inserted when the apertures of the socket are not visible to the person inserting the lamp, and which will afford an indication to the person so inserting the lamp, that the lamp has been fully seated in place, and that the proper contacts have been established within the socket.

A still further purpose is to provide a socket in which the lamp to be inserted can be rotated only substantially 90 in a predetermined direction, and must be rotated in the opposite direction for the same angular distance when it is withdrawn therefrom.

Another object is to provide a socket in which the tube is unlikely to be left in a partly insorted position and unlikely to be broken when trying to remove it.

Accordingly I provide a body of insulating material containing two oppositely disposed spring contacts adapted to be engaged by the prongs of a lamp tube. The face of the body is preferably provided with a Z-shaped slot with an entrance at one corner so arranged as to permit the sidewise insertion of the prongs or pins of the tube through the entrance slot after which the tube may be rotated so that the prongs will slide along the upper and lower branches of the Z slot until they reach the ends of the slot in which position the prongs will snap into recesses in the contacts. A rotor is also preferably provided in the body so as to guide the tube in its rotation and cover the slots adjacent the contacts. This rotor is so shaped with respect to the spring contacts that it tends to turn automatically to the on" or "013 position.

Further purposes and advantages of my invention will be apparent from the following speciilcation and irom the drawing annexed, wherein:

t Fig. l is an end view of thesocket of my invenion.

Fig. 2 is a face or front view of the socket from the side where the lamp prongs enter.

Fig. 3 is a rear view showing the lamp pins ir "011 or closed circuit position.

Fig. 4 is a sectional view of Fig. 3, upon tlu lines :c-at.

mm. 5 is a sectional view on the lines v -y oi Fig.6 is a perspective view of the rotor member of the socket.

Fig. 7 is a detail view showing the position of with an entrance [4 at one corner of the slot. This slot has a central portion l5 with upper and lower branches l6 each terminating in a tip H. The width of the slot and of the entrance is slightly greater than the diameter of the Prong to be received. The end of the body preferably has a recess IS with surfaces sloping toward the entrance slot 14 so as to facilitate insertion of the tube prongs. The edge 19 of the entrance slot is rounded off so as to minimize the possibility of destructive pressure being applied to it by rotation of the tube prongs.

An abutment 20 may be provided for preventing the contacts from touching each other. The tips of the spring contacts are spaced apart adjacent the entrance to the slot so as to admit the insertion of the tube prongs without the prongs connecting or shorting across the tips.

When the two prongs have been slid fully into the center of the slot, the tube can be twisted or rotated axially so that the prongs slide along the upper and lower branches and the prongs engage the contacts and spread them apart until'the prongs reach the wedge shaped recesses or notches 2| in the contacts. The walls of these notches are shaped so as to provide a sort of camming action on the prongs and thus assist in seating the prongs into the notches at'the same time that the prongs reach the tips I! of the slots thus indicating to the operator that the tube is properly placed.

The tips ll of the slots form pockets which register with the contact recesses 2| and the bottoms of the pockets serve as stops to limit the rotation of the tube being inserted, one pocket facingupward toward the entrance end and the other pocket facing in the opposite direction.

It will be seen that the limits imposed by the dimensions of the 2 slot allow the lamp to be rotated only in one direction, and for only about 90", before the bottom portions of the lamp pins are seated atthe respective extremities of this slot. Likewise when the lamp is to be removed from the socket, the direction of rotation will be the reverse from that which allowed it to be seated, and likewise will be similarly limited as to angular extent.

I also prefer to provide a rotatable member 24 which is seated in a bearing 25 behind the slot in the front of the body, and in front of the contacts I2 and serves as a support for the prongs of the tube and also as a guard or shield to prevent accidental engagement with the contacts. This member 24 has a hub 26 located between the contacts 12 so as to keep them apart and tend to hold the member 24 in the open circuit or off position before insertion of the tube prongs. This member 24 has a slot or groove 21 which permits the tube prongs to be inserted and then permits rotation of the tube and the member 24 which thus guides or supports the tube. This member 24 may also have an extension 28 supported in a bearing 29 in the back plate. The abutment 20 may be omitted when the hub 24 is used. This member 24 completely conceals and protects the contacts and yet permits the tube and its prongs to be inserted and twisted or rotated until it-is resiliently locked or held in the closed circuit or "on position. Of course the tube is demounted by reverse action.

Figs. 7 and 8 show the position of the tube prongs and the rotor with respect to the spring contacts in the off and partly "on positions respectively. As a result of this construction, the

springs tend to turn the rotor and tube away from the position of Fig. 8 either to the on" or off position. Consequently there is little if any danger of unintentionally leaving the parts partly on or partly off as is the case in my former application.

The springs exert pressure on the prongs tending'to rotate the parts to the fully on or fully off position. The springs also tend to return the rotor to the off position in case the tube prongs are pulled out while the rotor is partly turned from its off position. 1

I claim:

1. A tube socket having a body with a Z-shaped slot in the face thereof with a single entrance slot for the sidewise insertion of tube prongs directly into the main central portion of said Z-shaped slot, the ends of the Z-shaped slot extending on opposite sides of the main central portion, and a pair of spring contact arms mounted in the body and having movable tips disposed on opposite sides of the main central portion of said Z-shaped slot and a rotatable member mounted between the movable tips of said contact arms so as to cover the ends of said arms and having a groove in alinement with the entrance slot for the passage of the tube prongs whereby the tube prongs may be inserted sidewise through said entrance slot into said groove and so that said member may be rotated by the prongs of a tube so inserted whereby the arms are spread apart by the action of the prongs.

2. A tube socket containing spaced spring contacts and having a Z-shaped slot in its face with an entrance to the main central portion of said slot adjacent the contacts and a rotatable member mounted between said contacts and having a groove capableof being positioned in alinement with said main central portion of said slot so as to afford entry thereinto for. tube prongs, said rotatable member substantially covering the side arms of said Z-shaped slot when the groove of the rotatable member is in said position of alinement with the central portion of said slot.

'3. A tube socket comprising a body containing oppositely positioned spring contact arms having pockets for receiving tube prongs, the walls of each pocket being V-shaped and a slotted rotor mounted in thesocket between the spring contact arms and adapted to be rotated from an oif" to an on position by the rotation of a tube having spaced prongs when said prongs are slid sidewise into the rotor slot, said rotor having a hub with abutments normally fitting in said pockets in the off position of said rotor, said hub being of materially less diameter across said abutments than the distance from the outside of one prong to the outside of the opposite prong of the tube so that when the tube is rotated slightly less than 45 degrees or slightly more than 45 degrees from the oif position the spring contact arms will rotate the rotor either back to the off" position or to the on" position, said body having a single slot at one end leading to the slot in the rotor when said rotor is in the off position.

4. A tube socket having a body with a Z-shaped slot in the face thereof with a single entrance slot for the sidewise insertion of tube prongs directly into the main central portion of said Z-shaped slot, the ends of the Z-shaped slot extending on opposite sides of the main central portion, and a pair of spring contact arms mounted in the body and having movable tips disposed on opposite sides of the main central portion of said Z-shaped slot whereby the tube to one end of the main central part of the Z-shaped slot, a rotor mounted in said body between said i contacts and having a transverse groove adapted to extend in alinement with the main central part of the Z-shaped slot in the body when the tube prongs are inserted sidewise through the entrance slot into the main central part of the Z-shaped slot, said latter slot having its ends extending on opposite sides of the main central part so that the inserted tube prongs are directed laterally when the tube-is rotated, whereby said prongs may make connection with said contacts within said chamber.

6. A socket for a tube having two spaced prongs comprisingan insulating body having a chamber with two spaced contacts to receive the prongs of a tube and having an opening in its face leading to said chamber, said body having an entrance slot substantially in the center of one end leading to said opening, said body having pockets in the opposite sides of the opening registering with the respective contacts, one pocket facing toward the end of the body in which the entrance slot is located and the other pocket facing in the opposite direction so that the prongs of the tube may be inserted sidewise through said entrance and then rotated to bring one prong into one pocket and the contact adjacent thereto and simultaneously bring the other prong into the other pocket and the contact adjacent thereto.

MILTON ALDEN. 

